Cranberries are grown in bogs having relatively flat bottom surfaces that are surrounded by dikes. During harvesting, these bogs may be flooded with water to facilitate picking or they may be kept relatively dry for certain types of harvesting operations. The cranberry vines are rooted in the bottom of the bog and form a tangle of vines reaching approximately one foot high. The cranberries themselves are attached to the ends of tips or tendrils that extend from the base of the vines roughly every six to eight inches.
A conventional technique for harvesting the cranberries is to push a harvesting machine over the vines. The machine lifts the vines that are near the bottom of the bog and cuts them to allow new growth to form. Simultaneously, the machine separates the cranberries while leaving the tips intact. It is conventional for the machine to include conveying means that convey the cranberries to sacks or boxes located alongside the machine.
Conventional harvesting machines suffer from a number of disadvantages. First, it is difficult to maneuver these devices around corners and edges of the bog, and especially when wanting to reverse the machine's motion of travel. Currently, an operator must shift the drive motor to neutral, disengage the machine's wheels, and back the machine up and turn it to the opposite direction. A second problem is in that the pruning knives are often powered by the same systems used to propel the machine through the bogs. Typically, the motor drives the machine wheels, and from the same linkage, drives the pruning knives as well. Although it is desirable to operate the knives only while the machine is moving forward, there are times when it would be helpful to be able to keep the pruning knives operating at a constant speed while having the capability to speed up or slow down the machine's translational speed. Thus, a need exists for an improved cranberry harvesting device that avoids the above-described problems.